Answer:
b + b + 7 = 23
2b + 7 = 23
Step-by-step explanation:
b = girls
b + 7 = boys
Answer:
60
Step-by-step explanation:
First we divide 5 from 20 then we get 4 so 4 x 15 would be 60.
100% - 81% = 19%
19% did not pass.
Answer: 5040 7-digit numbers
Step-by-step explanation:
Permutations:
1: 1 ==> 1 permutation ==> 1 ==> 1!
12: 12, 21 ==> 2 permutations ==> 1*2 ==> 2!
123: 123, 132, 213, 231, 312, 321 ==> 6 permutations ==> 1*2*3 ==> 3!
7-digits: 7!=
1*2*3*4*5*6*7=5040 7-digit numbers
